The fire alarm monitoring company called the Boston Fire Department to alert them about the fire.

"Upon arrival, heavy fire showing -- basement and first floor. The fire blew out the first floor and started extending up the second and third. We moved all the firefighters away from the building and are conducting exterior operations only," Boston Fire Department Chief John Hassett said.

The fire was under control by 6 a.m. with firefighters dousing hot spots. Officials said they were concerned about the structural integrity of the building that was being renovated.

There were no reports of any injuries.

Traffic was diverted from the area, and motorist were urged to seek alternate routes.

MassDOT has opened the South Boston Bypass Haul Road to all vehicles to relieve traffic issues related to the fire.

NewsCenter 5 and WCVB.com will have more information when it becomes available.

REPORTING LIVE FROM WRENTHAM, I'M PAM CROSS, WCVB, NEWSCENTER 5. AND A FIRE IN A SOUTH BOSTON BUILDING AT ONE POINT WENT TO AN EIGHT ALARMS AFTER IT STARTED THIS MORNING. THE QUESTION IS HOW DID IT START? JIM LOKAY IS ON THE SCENE WHERE BUSY SUMMER STREET HAS BEEN CLOSED. IT'S BEEN A ROUGH AFTERNOON. EARLY THIS MORNING, MAKING SURE THAT BUILDING STAYED UP IS THE MAIN CONCERN. THERE'S A COLLAPSE ZONE NEARBY, BUT FOR THE PEOPLE THAT LIVE AND WORK NEARBY, IT'S BEEN A MAJOR DISRUPTION. THERE'S A LOT OF NOISE, AND TONS OF SMOKE AND FLAMES. IT WAS QUITE A THING TO SEE. AND HOURS LATER, AS FIREFIGHTERS TRIED TO CONTAIN THAT'S LEFT OF THE FIRE ON SUMMER STREET, MARIO KHAN WHO LIVES ACROSS THE STREET IS JUST OBVIOUSLY TO GET TO HIS CAR. AT ONE POINT THIS WAS AN EIGHT-ALARM OPERATION IN A PRIMARILY VACANT BUILDING. IT'S A FIVE-STORY BRICK BUILDING AND UNDERGOING RENOVATION. THERE WERE CLEANERS IN THE BUILDING, BUT THEY WERE OUTSIDE BY THE TIME WE GOT HERE. INVESTIGATORS TALKED TO THOSE WORKERS AND THE 102-YEAR-OLD BUILDING IS LARGE, THICK TIMBER COLUMNS AND THAT FORCED FIREFIGHTERS TO CLEAR OUT EARLY ON. IT WAS A PRETTY EASY DECISION TO GO IN DEFENSIVE OPERATIONS BECAUSE OF THE LARGE VOLUME OF FIRE, AND YOU KNOW, WE SAFELY GOT EVERYONE OUTSIDE FROM THE FRONT AND THE BACK AND WENT A LONG WAY TO PREVENTING INJURIES. BUT THE AFTERMATH HAVING A MAJOR AFFECT ON TRAFFIC AND MANY DRIVERS CONFUSED AND IT'S NOT OVER YET. THE GOAL TO BE TO TRY TO GET THIS STREET OPEN FOR THE MORNING COMMUTE. BACK HERE LIVE, THIS ACCESS ROAD THAT RUNS UNDERNEATH THAT SUMMER STREET BRIDGE, ONE OF MANY THAT REMAINED CLOSED, TRYING TO GET IT BACK OPEN FOR THE EVENING, A LOT OF DRIVERS DON'T KNOW HOW TO ACCESS THIS. AND PRELIMINARY ESTIMATES AS FAR AS DAMAGE IN THE BUILDING,